Kirkland Signature

Is Kirkland Signature third-party tested?

Yes — as of 2026-09-21, Kirkland Signature holds 4 third-party certifications across 2 independent testing programs: Labdoor, USP Verified. Every certification below links to the certifying body's official listing so you can verify it at the source.

Registries checked (as of 2026-09-21): Informed · NSF · USP (Products meet USP's standards for ingredient identity, potency, and manufacturing quality.) · Labdoor (Products are independently laboratory-tested for purity and potency and assigned a letter grade.) · BSCG